Siddarth Koduru Joshi

Space-based quantum key distribution (QKD) overcomes the limits of distance between terrestrial users caused by losses in optical fibre. Thus, it is the most promising method to establish a global scale QKD network. While the first QKD platform in the space - “the Micius satellite” – was a ground-breaking proof of principle demonstration, it is not a commercially favourable solution. We present our Cube-Sat payload design which has a more economically viable key-rate. The whole system is consisting of two parts, a 2U transmitter payload in Cube Satellite and an Optical Ground Station (OGS) working as receiver. The system is designed for polarisation based BB84/Decoy-State protocol with 100Mhz key transmission rate. In order to avoid the light pollution near the metropolitan centres and provide flexibility, we present our progress towards a mobile OGS which will be able to act as a receiver for the quantum signal.

Violation of a Bell inequality can be used to generate certified random numbers. Given the high rate at which pairs of entangled photons can be produced, they constitute promising candidates for high rate randomness generation. However, this requires closing the detection loophole. Here we present our progresses toward an experimental demonstration of randomness generation with photons, certified by the violation of a Bell inequality with a closed detection loophole.